Pyrotechnic, whistle, and method of making

ABSTRACT

A pyrotechnic whistle and method of producing same which prevents a minimum danger of explosion formed of a tubular reaction chamber and a pyrochemical mixture formed by mixing together a salt of salicylic acid and an oxidizing agent. Finely divided titanium is added to the pyrochemical mixture or to other pyrochemical mixtures formed of aromatic acids and oxidizing agents to provide a trail of glitter when the pyrochemical mixture reacts.

lltiiteel @ttes atet [191 Degn [54] lPYlRU'lECl-lNlC, WHISTLE, AND

METHQD 01F MAKING [76] Inventor: Ralph G. Degn, 214 A University Village, Salt Lake City, Utah 84108 [22] Filed: Oct. 7, 1970 [21] App]. No.: 78,921

[52] 11.5. Cl. ..102/31,149/38, 149/39, 149/40, 149/41, 149/42, 149/43, 149/44 [51] lnt. Cl. ..C06d 1/00 [58] Field of Search ..l02/31; 149/42, 44, 114, 85, 149/38, 39, 40, 41, 43

[56] References Cited UNITED STATES PATENTS 3,033,715 5/1962 Preckel ..149/99 X 3,033,718 5/1962 Preckel... ....149/99 X 3,088,858 5/1963 Camp ..149/99 X [451 ,llan.23, 1973 3,093,523 6/1963 Besser ..149/99 X 3,103,458 9/1963 Besser et al.... 149/99 X 3,228,815 1/1966 Henry et a1. ....149/99 X 3,309,250 3/1967 Falterman et a1. ..149/42 3,396,060 8/1968 Piccone ..149/42 Primary Examiner-Stephen J. Lechert, .lr. AttarneyH. Ross Workman [57] ABSTRACT 10 Claims, N0 Drawings PYROTECIHINHC, WHISTLE, AND METHOD OF MAKING BACKGROUND 1. Field of the Invention The invention relates to pyrotechnic devices and, more particularly, to a novel pyrotechnic whistle which is remarkably safe to make and use and which provides sound as well as novel visual effects.

2. The Prior Art Pyrotechnics is the art and science of creating and utilizing the heat effects and products from exothermically reacting, predominantly solid mixtures or compounds when the reaction is generally non-explosive and relatively slow, self-sustaining and self-contained. Pyrotechnics is one of three closely related technologies, the other two including explosives and propellants. Pyrotechnics is nearly exclusively concerned with solid ingredients while explosives and propellants may be solids or liquids.

A pyrotechnic process differs from ordinary combustion by not requiring the presence of ambient air, at least not in a predominant and essential way. Once the pyrotechnic process is triggered by a small external force, it may take its course in complete isolation from external chemical influences. Except at the point of initiation, pyrotechnic devices employ no moving parts or delicate components and perform equally well on land, in water, or in air. Most commonly, pyrotechnics are used to provide light and sound effects.

Pyrotechnic whistles are well-known in the art. It has been found that when pyrochemical mixtures consisting of crystals of certain acids of aromatic structure in combination with oxidizer salts are placed in a hollow tube, a shrill whistling sound is produced when the acid crystals and oxidizer salts react. The active substances most often used in the pyrochemical mixtures of prior art whistles include gallic acid (3, 4, trihydroxybenzoic acid), the potassium salts of benzoic acid, and of 2, 4 dinitrophenol, and of picric acid (2, 4, 6 trinitrophenol). Common oxidizing agents are potassium chlorate, potassium perchlorate or potassium nitrate.

While the precise mechanism producing the shrill whistle is not known, it is currently believed that the decomposition of aromatic acids through the oxidation process progresses in an oscillating manner whereby the crystals react in a rhythmic fashion, the reaction accelerating and stopping at generally uniform, closely spaced intervals. The rhythmic acceleration and stoppage of the reaction leads to an alternation of pressure and rarefaction in the tube. The pressure oscillation develops a sound the pitch of which is dependent upon the length of the tube. It has been found that various compositions are capricious in their ability to produce whistles and even products having identical chemical composition produced in the same batch but not pressed at the same time into tubes yield widely varying whistle pitches.

It has been found that the most common pyrochemical mixtures are extremely dangerous in that they are explosive in nature. Unusual care must be taken to prevent the mixtures from detonating while they are being placed in the reaction chamber or tube. Further, some of the compounds, for example gallic acid, have proved extremely difficult to obtain and, therefore, are

very expensive. Moreover, the nature of the prior art whistles is such that there are practically no visually observable effects resulting from the reaction of the pyrochemical compound. On the contrary, only a small yellow flame exists which is partially obscured by the tube or reaction chamber.

BRIEF SUMMARY AND OBJECTS OF THE INVENTION The present invention comprises a novel pyrotechnic whistle comprising a pyrochemical mixture and an entirely novel titanium component added to the pyrochemical mixture to provide a bright silver shower of glitter upon reaction of the mixture. In addition, a novel pyrochemical mixture is provided which is nonexplosive and highly safe during all stages of preparation of a pyrotechnic whistle.

It is, therefore, a primary object of the present invention to provide a novel pyrotechnic device which is highly safe, relatively inexpensive and provides novel visual and sound effects.

It is another primary object of the present invention to provide an improved method of producing pyrotechnic whistles having combined visual and sound effects.

These and other objects and features of the present invention will become more fully apparent from the following description and appended claims.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In this specification, a pyrotechnic mixture is defined to include a mixture of salts of gallic acid, benzoic acid, 2, 4 dinitrophenol, picric acid and salicylic acid and an oxidizer salt in such proportions as to create a pyrotechnic reaction.

I have found an improved pyrotechnic mixture which utilizes a salt of salicylic acid as an active ingredient. Salicylates are highly stable compounds and are not considered hazardous at common temperatures. Moreover, salicylates can be easily obtained at low cost from a wide variety of chemical supply houses in powdered or granular form.

Salicylate salts have proved to be highly effective as an active agent in pyrotechnic whistles when mixed with oxidizing agents, in the form of salts, and placed in a hollow tube. Although many common oxidizing agents will react to some degree with salicylates, some oxidizing agents are far more effective than others to create a whistle-producing rhythmic alternation of pressure and rarefaction in a tube. The most effective oxidizing agents discovered during my experimentation are potassium perchlorate, potassium chlorate and barium chlorate.

The whistling sound is produced effectively when a reaction chamber which may be, for example, a paper tube is used. Clearly, any suitable reaction chamber could be used. The tube must have: a diameter which is sufficiently small to develop the resonance necessary to produce the whistle. Although tubes having a diameter as large as three inches have been successfully used, tubes having an inside diameter of less than 1 inch have been used with far greater success. Also, I have found that the small diameter tubes should be convoluted or parallel wound so as to have a comparatively smooth bore. Tubes that are spirally wound have proved less successful because, after ignition, the pyrotechnic reaction takes place all along the spiral seam of the tube thereby making the reaction non-uniform and defeating the ability of the reaction to develop a whistle.

I have found also that the tube may be open at both ends, if desired. However, since ambient air is not essential to the reaction, the tube may have only one open end.

The novel invention herein disclosed is best understood by a description of the method of producing improved pyrotechnic whistles in the manner setfort in the following examples.

EXAMPLE 1 A pyrochemical mixture was produced by weighing approximately 16 grains finely powdered sodium salicylate. Sodium salicylate is the sodium salt of orthohydroxybenzoic acid (HOC,H COOH). The powdered sodium salicylate was mixed thoroughly with about 8 grains of potassium perchlorate (K an oxidizing agent. The proportion (weight/weight) of salicylate to perchlorate was on the order of about 2:1.

A parallel wound Kraft paper tube having an inside diameter of five-sixteenths inch and a length of 5 inches was obtained. One end of the tube was placed over a vertical dowel having a one inch length and the pyrochemical mixture was rammed with hand pressure into the other end of the tube. The tube was removed from the dowel. It was found that the dowel created a space in the 1 end of the tube of approximately 1 inch between the pyrochemical misture and the end of the tube. The one inch space was adequate to allow resonance to develop in the tube to produce a whistle. Thereafter, a one-eighth inch diameter fireworks safety fuse, otherwise known as a Bickford fuse was situated adjacent the pyrochemical mixture in the one end of the tube. A conventional paper nosing was twisted around the fuse to hold the fuse in place.

Upon ignition, it was found that the pyrochemical mixture developed a very small yellow flame and an unusually shrill whistle.

EXAMPLE 2 Three batches of pyrochemical mixture were prepared by practicing the steps of Example 1 as described and to each of the batches finely divided titanium metal of 16, 24 and 80 mesh, respectively, was mixed thoroughly so that the salicylatezoxidizing agentztitanium proportions (weight/weight) were on the order of about 112203 When the pyrochemical mixture was ignited, it was observed that, in addition to the unusually shrill whistle, a bright silver shower of sparks and glitter were produced giving an unusual visual effect accompanying the shrill whistle. No retardation of the salicylateperchlorate reaction was observed and the volume produced by the whistle did not appear to diminish because of the titanium. The character of the sparks according to the size of titanium particles as set forth in Table I.

TABLE I Character of Sparks Titanium Particle Size long life, large brilliant sparks l6 mesh moderate life, large brilliant sparks short life, small brilliant sparks EXAMPLE 3 24 mesh 80 mesh The procedure of Example 2 was followed except that the weight/weight proportions of sodium salicylate, potassium perchlorate and titanium were varied as set forth in Table 2, below.

It was found that the amount of titanium added between the ranges of 0.1 and 0.5 proportional parts did not significantly affect the reaction of the salicylate and perchlorate. Increasing the amount of titanium was EXAMPLE 4 The steps of Example 2 were practiced except that the potassium chlorate was substituted for potassium perchlorate. The whistling was diminished but the amount and brilliance of sparks was comparable to the pyrochemical compound using potassium perchlorate.

EXAMPLE 5 The steps of Example 2 were practiced except that the tube was mounted so as to remain stationary and the potassium perchlorate, sodium salicylate and titanium were mixed in a weight ratio of 22110.3. Upon ignition, a high shrill whistle developed and simultaneously a broad trail of sparks resulted.

EXAMPLE 6 The steps of Example 2 were performed except that the tube was closed at one end with a clay plug and the tube was allowed to move as a conventional whistlechaser. A potassium perchloratezsodium salicylateztitanium ratio was 2.5:l:0.3. Upon ignition, the

shrill whistle was developed without loss of sound volume even though the tube moved at high speed. A

trail of brilliant sparks followed the tube. The higher perchloratezsalicylate ratio appeared more effective than the lower ratio of Example 6 when the whistle was allowed to move.

EXAMPLE 7 The steps of Example 2 were performed for a number of potassium perchlorate-sodium salicylate ratios ranging from l:1 to 2.5:1, while the titanium ratio remained constant at about 0.3. As the ratio approached 1:1 a greater amount of flame resulted upon ignition and large volumes of black smoke emerged. Only a slight whistle resulted. As the ratio approached 2.5:1, the whistle disappeared and only a hissing sound resulted. Greater whistling was developed as the lzl and 2.5:1 ratios converged and appeared optimum at a ratio of about 2.0: 1.

EXAMPLE 8 The steps of Example 2 were repeated four times to produce four separate pyrochemical compositions except that in each composition sodium salicylate was substituted by a different aromatic compound consisting of one of 3, 4, 5 trihydroxybenzoic acid and potassium salts of benzoic acid; 2, 4 dinitrophenol; and 2, 4, 6 trinitrophenol. Each of the compounds was mixed with potassium perchlorate, potassium chlorate, barium chlorate or potassium nitrate in the ratios shown in Table III, below. In all cases, the percentage composition of titanium was varied from a trace to 40 percent.

TABLE III Oxidizer Active Agent Approximate ratio Potassium Chlorate 3, 4, 5 Trihydroxybenzoic Acid* 3:1 Potassium Perchlorate Potassium Benzoate 2.7:l Potassium Nitrate Potassium Dinitrophenate [:27 Potassium Nitrate Potassium Picrate 1:1

*3 percent Red Gum added as a binder When ignited, the pyrochemical composition, in each case, produced a whistle and emitted a large number of brilliant sparks. The whistle diminished rapidly as the percentage composition of titanium increased from between about 25 percent to about 40 percent and above 40 percent no whistle developed.

EXAMPLE 9 A pyrotechnic mixture prepared as set forth in Example 2 was prepared and placed in tubes having lengths which varied over a wide range greater than 2.5 inches and it was discovered that length had no apparent effect on the ability of the pyrotechnic mixture to develop whistle sounds.

The invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore to be embraced therein.

What is claimed and desired to be secured by United States Letters Patent is:

1. A pyrotechnic device comprising a reaction chamber having at least one open end; an active pyrochemical mixture comprising (1) a salt of salicylic acid in powdered form mixed with (2) an oxidizing titanium.

2. A pyrotechnic device as defined in claim 1 wherein the particle size of titanium is between 16 mesh and mesh.

3. A pyrotechnic device as defined in claim ll wherein said salt of salicylic acid and oxidizing agent are mixed in a ratio of between l:l.0 and 1:2.5.

4. A pyrotechnic device as defined in claim 1 wherein said pyrochemical mixture comprises one part salt of salicylic acid and 1.0 to 2.5 parts oxidizing agent and less than 0.5 parts titanium mixed in a weight/weight/weight ratio.

5. A pyrotechnic device as defined in claim 1 wherein said chamber is a tube having a smooth bore and at least one open end.

6. A pyrotechnic whistle comprising a reaction chamber having an open end and a pyrochemical mixture comprising a finely divided salt of salicylic acid and an oxidizing agent selected from the group consisting of perchlorate and chlorate, the salt of salicylic acid and oxidizing agent being mixed together in proportions by weight of about l:l.0 to 2.5.

7. In a method of producing a pyrotechnic device, the steps of:

providing a reaction chamber having at least one open end;

preparing a pyrochemical mixture by finely dividing a salt of salicylic acid and mixing the salt with a solid oxidizing agent selected from the group consisting of perchlorate and chlorate;

mixing finely divided titanium with the pyrochemical mixture;

locating the pyrochemical mixture and titanium mixture within the reaction chamber.

8. A composition of matter comprising:

a pyrochemical mixture selected from the group consisting of 3, 4, 5 trihydroxybenzoic acid and a chlorate salt, benzoate and perchlorate salts, dinitrophenate and nitrate salts, and picrate and nitrate salts; and

finely divided titanium particles in a percentage composition of less than 40 percent.

9. A composition of matter as defined in claim 8 wherein all salts are potassium salts and the 3, 4, S trihydroxybenzoic acid:chlorate proportions are on the order of about 3:1; the benzoatezperchlorate proportions are on the order of about 2.7:1; the dinitrophenatemitrate proportions are on the order of about 1:2.7 and the picrateznitrate proportions are on the order of about 1:1.

10. A pyrotechnic device comprising a reaction chamber having at least one open end and an active pyrochemical mixture comprising (1) an active agent selected from the group consisting of 3, 4, 5 trihydrobenzoic acid, benzoates, 2, 4 dinitrophenols, 2, 4, 6 trinitrophenols, picrates and salicylates; (2) an oxidizer selected from the group consisting of chlorates, perchlorates and nitrates; and (3) finely divided titaniurn. 

2. A pyrotechnic device as defined in claim 1 wherein the particle size of titanium is between 16 mesh and 80 mesh.
 3. A pyrotechnic device as defined in claim 1 wherein said salt of salicylic acid and oxidizing agent are mixed in a ratio of between 1:1.0 and 1:2.5.
 4. A pyrotechnic device as defined in claim 1 wherein said pyrochemical mixture comprises one part salt of salicylic acid and 1.0 to 2.5 parts oxidizing agent and less than 0.5 parts titanium mixed in a weight/weight/weight ratio.
 5. A pyrotechnic device as defined in claim 1 wherein said chamber is a tube having a smooth bore and at least one open end.
 6. A pyrotechnic whistle comprising a reaction chamber having an open end and a pyrochemical mixture comprising a finely divided salt of salicylic acid and an oxidizing agent selected from the group consisting of perchlorate and chlorate, the salt of salicylic acid and oxidizing agent being mixed together in proportions by weight of about 1:1.0 to 2.5.
 7. In a method of producing a pyrotechnic device, the steps of: providing a reaction chamber having at least one open end; preparing a pyrochemical mixture by finely dividing a salt of salicylic acid and mixing the salt with a solid oxidizing agent selected from the group consisting of perchlorate and chlorate; mixing finely divided titanium with the pyrochemical mixture; locating the pyrochemical mixture and titanium mixture within the reaction chamber.
 8. A composition of matter comprising: a pyrochemical mixture selected from the group consisting of 3, 4, 5 trihydroxybenzoic acid and a chlorate salt, benzoate and perchlorate salts, dinitrophenate and nitrate salts, and picrate and nitrate salts; and finely divided titanium particles in a percentage composition of less than 40 percent.
 9. A composition of matter as defined in claim 8 wherein all salts are potassium salts and the 3, 4, 5 trihydroxybenzoic acid: chlorate proportions are on the order of about 3:1; the benzoate: perchlorate proportions are on the order of about 2.7:1; the dinitrophenate:nitrate proportions are on the order of about 1: 2.7 and the picrate:nitrate proportions are on the order of about 1:1.
 10. A pyrotechnic device comprising a reaction chamber having at least one open end and an active pyrochemical mixture comprising (1) an active agent selected from the group consisting of 3, 4, 5 trihydrobenzoic acid, benzoates, 2, 4 dinitrophenols, 2, 4, 6 trinitrophenols, picrates and salicylates; (2) an oxidizer selected from the group consisting of chlorates, perchlorates and nitrates; and (3) finely divided titanium. 